Harpenden

Earlier Climate Change Notes

Climate change group 21.4.2020

This new section of study on Materials is very interesting, providing much to consider in terms of the environment and economics.

It is prefaced by the mantra, Reduce, Reuse, Recycle. Industries have come to realise that there is value in material that has been used. It is cheaper to buy and to access than the original source and is readily available, locally.

A new way of thinking is emerging, starting with another slogan; Take, Make, Waste. By using recycled materials, we extend the life of the material. Significant environmental and economic gains are made as the material’s transformation moves round in a loop, leading to new concept of circular economics.

Some of the items are quite a surprise, for instance, concrete is a commonplace substance at the heart of almost all building, fairly harmless, then. It unfortunately has a high carbon footprint. The crushed limestone and aluminosilicate clay are roasted in a giant kiln at 2,640 degrees F. That is extremely hot! The heat splits the limestone’s calcium carbonate into calcium oxide and the desired lime content and also co2, which is waste that escapes to the atmosphere. The clinker is milled to a fine powder, cement. Thankfully, however, there is a new industry for carbon capture. They may well have moved in to the cement works.
The ozone layer hole over the Antarctic was caused by escaping refrigerant gases. The Montreal Protocol 1987 ensured that ozone depleting gases were phased out. These were CFCs and HCFCs, Chlorofluorocarbons and Hydrochlorofluorocarbons, which were also used in dry cleaning and aerosol sprays. The hole in the ozone layer is now mending. It helps to filter out harmful rays in sunlight. New Zealanders were required to wear sun-cream to go out of doors. Most importantly, the disposal of fridges requires specialist handling to prevent escaping gas.

Recycling paper is old news now. It can be recycled five times before its fibres break down. Paper of all sorts comes from timber, immense quantities of it. The maths is easy, we should be felling five times less forest for paper. Very good news indeed. Kitchen and toilet tissue can be bought from recycled sources.

Henry Ford made the first car with bio plastic bodywork in 1941, 80 years ago. It had a 60 horse power engine! War time hunger for steel made such thinking urgent. We now produce 301 million tons of plastic a year, 83 pounds per person. It is a truly wonderful invention in very common use, it is the Plastic Age. We no longer need to throw it all away as some can be recycled. In contrast to petro-plastics, bioplastics can reduce emissions and sequester carbon. Bio-plastics decrease greenhouse gases, can be used in 3-D printing and some are biodegradable at low temperatures.

The current plastic rubbish discarded, not sent to recycling or regulated tips, is ending up in rivers and oceans creating grave problems and predicted to outweigh fish by 2050. Bio plastics have a great future.
Water, essential to life, arrives at our homes fit to drink. Considerable energy is required to pump it around our neighbourhoods. Hot water uses a quarter of our domestic energy, world-wide. Low flush toilets and water efficient washing machines use almost a fifth less water. Water efficient shower heads and dish washers also reduce consumption. Energy generation by nuclear and fossil fuels requires vast amounts of water for cooling. In USA that is roughly half the water consumption!

Much to reflect on, then.

Pat Jacques

News 11.4.20

Supplementary Bulletin

Coronavirus mustn’t eclipse Climate Change concerns

All our minds are understandably focussed at present on the Covid-19 pandemic which is by definition a global issue. But it should not be allowed to detract from the other, necessarily more enduring, global concern, namely Climate Change.

Meetings this year of Harpenden U3A’s Climate Change group – before the ‘lockdown’ came into force – addressed two key areas of consideration, namely LAND USE and TRANSPORT. We considered ways in which land is used, in the context of exhausted soils, abandoned farms, in hot dry countries and droughts, floods, and impending rises in sea level as the climate warms. Crop failures lead to huge human migration. All these matters are set against the pressing need to feed an ever-increasing population on a shrinking area of fertile land. Clearly there is a range of massive issues to be addressed.

Resolutions can be simple; in dry countries, on many smaller farms, a hollow around each new plant can be created to retain the moisture from often limited rainfall, thereby resisting desertification. Exhausted soils need agricultural regeneration, requiring compost or manure, bringing microbial, nutritional benefits and moisture retention. Planting new crops through existing ground cover reduces the need for insecticidal sprays; it is now much used in Australia.

Allowing cattle and sheep to roam, grazing in pasture with trees, gives the animals shade and their manure enriches the land. Planting areas with a mix of plants reduces the need for costly insecticide and pesticide. Where chemical fertiliser, pesticides and fungicides are used less, apart from the obvious financial benefit, there are fewer harmful emissions from fossil-fuelled agricultural machinery. Simpler plans are more suitable on smaller farms in the developing world.

Increasingly, larger farms now have their own anaerobic digesters, where organic matter is placed in the tank and the air withdrawn, allowing the organic matter to decompose. The CO2 and methane is ducted away to create biogas an alternative fuel, in place of diesel or petrol fossil-fuel, for powering the engines in vehicles and machines or for generating electricity. The residual digestate is an excellent organic fertiliser. Good news then, utilising unwanted material to turn it into fuel and fertiliser! Waste food is now used on a commercial scale.

At our next meeting we looked at the many Climate Change issues related to transport. Almost everything we use is shipped by air, sea or land consuming fossil fuel. Freight ships are especially damaging environmentally, being fuelled by poor quality high-sulphur diesel, creating noxious nitrogen and sulphur dioxide as well as particulate exhaust emissions. Their fuel efficiency is also relatively poor, producing excessive global-warming CO2 emissions. These ships now change to a better grade of fuel when approaching port and nearby inhabitants develop far fewer serious respiratory health issues.

One way to reduce both pollutant and CO2 emissions from trains, trucks and cars is to make them more aerodynamic, so that there is less drag requiring less power and therefore less fuel is consumed in pushing them through the air. They also weigh less. The same applies to the smoothness or otherwise of a ship’s hull. Surprisingly the barnacles can impair a vessel’s fuel efficiency by 40%. To address this, hulls are increasingly being coated to prevent marine organisms from clinging to the surface.

Decreasing speed, reduces fuel and emission levels of all forms of powered transport, even though it has to be recognised that there are counterbalancing considerations. It could mean for example that if the speed limiters on a fleet of ten long-haul trucks were to be reset at say 50km/h instead of 56km/h (the present legal speed limit in the EU) then an additional (polluting) vehicle would be needed for the fleet to do the same work. (A further relevant factor is that drivers’ working hours are legally limited, mitigating against longer, i.e. slower, journey times).

High-speed trains save time but are hugely expensive, not least in terms of (compulsorily purchased) land cost. The track costs millions of pounds per mile as it needs to withstand an extremely heavy machine travelling and vibrating at high speed. The projected £100 billion-plus HS2 programme has encountered numerous obstacles including variable soils and rocks and has required many tunnels, greatly adding to costs. Countries with more wide-open landscapes than Britain can more easily build such high-speed lines.

In terms of remote working there is Telepresence a great advance on video conferencing, allowed workers to avoid travelling to conferences and “meet” more often. It is increasingly useful during the Covid19 crisis.

The aim of reducing emissions is twofold: to mitigate climate change and cut air pollution, improving the environment for better health.

Pat Jacques

CLIMATE CHANGE GROUP NEWSLETTER 4. MARCH 2020

Our January group meeting focused on Land Use in the context of exhausted soils, abandoned farms in hot dry countries, droughts, floods, and rising sea levels as the climate warms. Crop failures lead to huge human migration. All these matters are set against the pressing need to feed an ever-increasing population size on less land. Clearly there are a range of massive issues to be addressed.
Resolutions can be simple; in dry countries, on many smaller farms, a hollow around each new plant is created to retain maximum rain fall. Exhausted soils need agricultural regeneration, requiring compost or manure, bringing microbial, nutritional benefits and moisture retention. Planting new crops through existing ground cover reduces the need for insecticidal sprays.
Allowing cattle and sheep to roam, grazing in pasture with trees gives the animals shade and their manure enriches the land. Planting areas with a mix of plants reduces the need for insecticide and pesticide. Where chemical fertiliser, pesticides and fungicides are used less, there is a financial benefit and there is less emission from fossil fuelled vehicles. Simpler plans are more suitable on smaller farms in the developing world.
Increasingly, larger farms now have their own anaerobic digesters, where organic matter is placed in the tank, the air withdrawn, allowing the organic matter to decompose. The rising CO2 and methane are ducted away to be converted into biogas, which can be used to power vehicles and to generate electricity. The remaining digestate is excellent organic fertiliser. Good news then, utilising unwanted material to turn it into fuel and fertiliser! Our waste food goes to anaerobic digesters on a commercial scale.
In February we studied transport. Almost everything we use is shipped by air, sea or land in trucks using fossil fuel, freight ships use poor quality diesel, all creating emissions, damaging the climate.
Generally, reducing emissions from trains, trucks and cars is achieved by making them more aerodynamic to reduce drag, and weight, thus using less fuel and reducing emissions. Travelling a little slower, saves on fuel and emissions. Ships now change to a better fuel when approaching the port because inhabitants, nearby, have suffered serious ill health issues from emissions.
Barnacles growing on ships’ hulls create such drag that 40% efficiency is lost! Hulls are increasingly painted with a new substance that prevents marine organisms from clinging to the surface.
The high-speed trains save time but are hugely expensive. The track alone cost millions of pounds per mile as it needs to withstand an extremely heavy machine travelling and vibrating at speed. Our projected HS2 track has encountered many obstacles including variable soils and rocks and has required many tunnels, adding hugely to costs. Countries with wide open landscapes can more easily build such tracks.
Telepresence is a way of communicating, remotely. It is a technological advancement on video conferencing and saves a great deal of environmental damage from travel.
The aim in reducing emissions is twofold, it reduces climate changing chemicals in the atmosphere and leaves cleaner air for us, improving the environment for better health.
Pat Jacques.

Climate Change Group 2.12.2019

Educating girls, family planning and buildings and cities.

Our latest group topics have included better education for girls especially in developing countries, where they work for little or no pay in agrarian jobs. The section on educating girls and on family planning is very short and to the point. This is possibly the most important section of our set text, “Drawdown”.

Family planning measures are a critically important issue, worldwide. There are 75 million unplanned pregnancies a year and 45,000 in USA alone. It has been seen that as girls receive more education the rate of unplanned pregnancies and births reduces significantly. Most girls want to be able to plan the timing and number of their children but of course need the means to do so. There is an urgent need for female health clinics and the provision of contraception. Clearly educating young men in these matters is important too, but essentially there must be access to the means.

The second section is to do with buildings and cities, considering the carbon footprint of sourcing and creating them and of the energy used within buildings. Like energy production and the growth and distribution of food, it is a sector with heavy energy and resources requirements.

The development of carbon neutral buildings is essential, this involves a range of insulation including the ground level floor as well as the walls and ceilings and the management of heating and lighting.

Smart glass, which can reflect away heat and light and can dim as required, is a huge development, though the prototypes were started in the 1970s. We will all have seen the tinted windows in large office blocks and several of us have spectacles which respond to altered light conditions. This works by means of fine layers and the movement of ions between them.

The idea of green roofing, which grows in situ, needs careful preparation to seal the roof area underneath the soil. It insulates very well and helps neutralise atmospheric carbon. The planting can include general ground cover plants. Another sort of roofing can utilise small light-coloured metal chips which reflect away the heat and the light, reducing the need for or amount of air conditioning. To optimise the efficiency, the chippings have to be washed periodically.

Heat pumps to warm or cool rooms, work like fridges in reverse. They can use air, water or geothermal sources. In summer they take the warm air from outside and cool it for use inside, in winter they take cold air and warm it. The heat in the pumps is generated by compressing the air.

Cycle ways and pedestrian only streets are a great advantage, especially since they are free from exhaust fumes. Walking and cycling reduce the need for fossils fuelled vehicles. We also need a good network of cycle ways.

“John Lewis’s trucks to run on cow manure,” so goes the headline! The link here is that bio gas can be made from decomposing organic matter, as we saw last time, looking at anaerobic digesters. The carbon dioxide and methane rising from the decomposing matter is ducted away from the tanks to make biogas which is carbon neutral. This can be used as a fuel to power vehicles or it can be sent to power the electricity generating stations. The digestate, left in the tanks, can be used as a very nutritious fertiliser. We do need vast quantities of it to use instead of nitrogen fertilisers. Keep putting waste food into your special bin, it goes to the digester!

These processers also take farm slurry, which can trickle into water courses carrying nitrogen with them and causing great concern as it is believed to be toxic to fish and contributes to dead zones in the oceans.

There are very positive developments to help us to neutralise carbon in the atmosphere. Planting trees certainly helps, how could we do more of that, locally?

Pat Jacques.

Climate Change Group on Food. October 2019

This is a brief overview of our tour of food production:

We have discussed the many new developments in food production. The carbon footprint for the production and distribution of food is immense, almost the same as that for the production of energy.

Rice
One of the most rewarding changes is concerned with rice production. 20 percent of all our calories world wide comes from rice, thus it is a vastly important crop. As we know rice is traditionally grown in paddy fields and is planted out a handful at a time. It has been demonstrated that by planting individual rice grains and planting them out as seedlings, in an ordinary field, watering as required, produces between 50 to 100 percent more rice! It is hearteningly good news, especially since the world population has been doubling for many decades.

Regenerative agriculture
Regenerative agricultural practices restore the degraded land, no ploughing is required and only on-farm fertiliser. The purpose of this approach is to improve the quality of the soil over time. It increases organic matter, fertility, texture and water retention. It also helps create trillions of bacteria which feed the soil and the plants. Ploughing, by turning over the soil allows it to dry out.

Farmland irrigation
This takes water only to the plants, therefore saving water. It uses long pipes with small holes for the water to be released.

Silvopasture
Silvopasture allows cattle, sheep or deer to graze among trees. It counterbalances the methane produced by the cattle and sequesters carbon in the soil and provides a degree of shade. This system is the best to help farming finances, it enhances animal health and increases milk yield. The cattle keep the weeds down by feeding on the ground cover. Less fertiliser and pest control need to be acquired. Less water evaporates.

Our next series of discussions will take us into the need to educate girls and following that we are looking at the carbon footprint of buildings, this too, is immense. Many wonderful developments are in production and we look forward to enhancing our understanding of the issues and to seeing the newest ideas in hand.

Pat Jacques

Climate change group 28 September 2019

The Climate Change group has now had two meetings, in which we determined our plans for our course and chose our base text, which is Drawdown: the most comprehensive plan ever proposed to reverse global warming. Pub. Penguin, Ed. Paul Hawken. It is the best text for us as it is both positive and constructive in information and outlook, thoroughly substantiated by research and each short chapter written by experts in their field.

We have overviewed Energy, the first chapters, considered the material and weighed up the advantages of the best ones. Among the best are the Methane Digesters which comprise a tank which can be sealed, into this is loaded green organic matter, oxygen is sucked out. During the breakdown of the organic matter C02 and methane are released, these are ducted away to be processed into biogas, a fuel heat source for turbines to generate electricity. Also, the digestate left at the bottom of the tank is an excellent natural fertilizer for nourishing the land. This process can also be used with sewage.

I admire the economy of this thinking, to put in something you don’t need or want, leave it a while and achieve two things you really do want, electricity and excellent fertilizer! It is some of the neatest thinking I have seen. Through this means, we can cut down on chemical fertilisers and there is saving of those costs. There are of course the initial set up costs.

These digesters are both domestic or industrial scale. There are many thousands of these in Germany, where they are decommissioning nuclear generators. In England there are increasing numbers of these on farms and there is an application to build a new site for Anaerobic Digesters in Hertfordshire.

Our next theme is Food. The global warming generation involved in food production and distribution is colossal, almost as much as energy generation.

Our group experience includes economics, engineering, education, pharmaceutics, health and a great deal of wisdom!

Pat Jacques.